Substituted 5-alkynyl pyrimidines having neurotrophic activity

ABSTRACT

The present invention relates to a series of novel substituted 5-alkynyl pyrimidines, pharmaceutical compositions which contain them, methods for their preparation, and their use in therapy, particularly in the treatment of neurodegenerative or other neurological disorders of the central and peripheral nervous systems, including age related cognitive disorders such as senility and Alzheimer&#39;s disease, nerve injuries, peripheral neuropathies, and seizure disorders such as epilepsy.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 35 U.S.C. 371 national phase application ofInternational Application No. PCT/US01/23088, filed Jul. 20, 2001, whichclaims the benefit of U.S. Provisional Application No. 60/220,348, filedJul. 24, 2000, both of which are incorporated herein by reference intheir entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a series of novel substituted 5-alkynylpyrimidines, to pharmaceutical compositions which contain them, tomethods for their preparation and to their use in therapy, particularlyin the treatment of neurodegenerative or other neurological disorders ofthe central and peripheral nervous systems including age relatedcognitive disorders such as senility and Alzheimer's disease, nerveinjuries, peripheral neuropathies, and seizure disorders such asepilepsy.

Dementing disorders such as age-related cognitive disorders, e.g.,senility or Alzheimer's disease are medical conditions for which thereare currently only limited therapies. Although studies suggest thatmultiple neurotransmitter systems are involved in senile dementia, aloss of cholinergic neurons and a severe depletion of cholineacetyltransferase appear to show the earliest and strongest correlationwith functional cognitive impairment [see P. T. Francis et al.,Neurochemical Studies of Early-onset Alzheimer's Disease. N. Engl. J.Med., 313, 7 (1985); R. T. Bartus et al., The Cholinergic Hypothesis: AHistorical Overview, Current Perspective, and Future Directions. Ann. N.Y. Acad. Sci., 444, 332 (1985); F. Hefti and L. S. Schneider, NerveGrowth Factor and Alzheimer's Disease, Clin. Neuropharmacol., 14, S62(1991)]. Several groups have attempted to stimulate cholinergic activityby blocking the breakdown of acetylcholine with acetylcholine esteraseinhibitors or by introducing muscarinic or nicotinic agonists [see R. T.Bartus et al., The Cholinergic Hypothesis of Geriatric MemoryDysfunction. Science, 217, 408 (1982); J. Varghese et al., Chapter 21.Alzheimer's Disease: Current Therapeutic Approaches. Annu. Rep. Med.Chem., 28, 197 (1993)]. The approved drugs COGNEX and ARICEPT areacetylcholine esterase inhibitors.

Nerve growth factor (NGF) is the best characterized neurotrophic factorthat is capable of inducing cell differentiation of neural cells andpromoting neurite sprouting. The neurotrophic protein NGF primarilyaffects cholinergic neurons in the central nervous system and may benecessary for their survival [see F. Hefti and P. A. Lapchak,Pharmacology of Nerve Growth Factor in the Brain. Adv. Pharmacol., 24,239 (1993)]. NGF is not systemically bioavailable, but if it is injectedor infused directly into brain, it prevents neuronal cell loss andrestores cognitive function in aged or lesioned rats or monkeys [see W.Fischer et al., NGF Improves Spatial Memory in Aged Rodents as aFunction of Age. J. Neurosci., 11, 1889 (1991)]. NGF effects ultimatelyresult in the stimulation of choline acetyltransferase, the enzyme forbiosynthesis of acetylcholine and the promotion of neurite growth.Consequently, small molecules that produce neurotrophic or “nerve growthfactor-like” (NGF-like) properties in mammalian cell cultures havepotential for use in the treatment of dementing disorders such asage-related senility or Alzheimer's disease and other neurodegenerativeconditions such as peripheral neuropathies, Parkinson's, stroke damage,transient ischemic attacks, trauma-head injuries or other nerveinjuries.

Since pancreatic cells producing insulin synthesize, secrete and arestimulated by nerve growth factor, another potential use of thecompounds of the present invention is in the treatment of diabetes. [SeeT. Rosenbaum et al., Pancreatic B Cells Synthesize and Secrete NerveGrowth Factor, Proc. Natl. Acad. Sci. USA, 95, 7784 (1998)].

There are several reports of small molecules that exhibit variousaspects of NGF-like activity. Isaxonine [2-(isopropylamino)pyrimidine]was developed as a neurotrophic pharmaceutical but the clinicalapplication was withdrawn, possibly due to toxicological effects [see S.Lehmann et al., Neurite Outgrowth of Neurons of Rat Dorsal Root GangliaInduced by New Neurotrophic Substances with Guanidine Group. Neurosci.Lett., 152, 57 (1993)]. Several 2-(piperazino)pyrimidine derivativeswere reported to possess NGF-like activity and are being studied furtherfor use in treating CNS degenerative diseases [see A. Awaya et al.,Neurotrophic Pyrimidine Heterocyclic Compounds. Biol. Pharm. Bull., 16,248 (1993)]. AIT-082(4[[3-(1,6-dihydro-6-oxo-9-purin-9-yl)-1-oxopropyl]amino]benzoic acid)is reported to enhance NGF action in cultured PC-12 cells and to restoreage-induced working memory deficits in mice [see P. J. Middlemiss et.al., AIT-082, A Unique Purine Derivative, Enhances Nerve Growth FactorMediated Neurite Outgrowth from PC-12 cells. Neuroscience Let., 199, 131(1995)]. The compound SR57746A is reported to have nerve growth factorpotentiating activity and is in clinical trials [see Fournier J, et al.Protective Effects of SR57746A in Central and Peripheral Models ofNeurodegenerative Disorders in Rodents and Primates. Neuroscience,55(3), 629–41, August 1993; U.S. Pat. Nos. 5,270,320 and 5,462,945]. Thecompound BW 394U, 2-amino-5-(4-chlorophenyl)thio-4-morpholinopyrimidine,is described as a potential antisenility agent [see Samano et. al., J.Heterocyclic Chem., 37, 183 (2000)]. In addition, WO98/12190,WO99/19305, WO00/59893, WO00/61562, EP0372934, EP0459819 and U.S. Pat.No. 5,075,305 disclose substituted pyrimidines having NGF-like activityand their possible use in treating CNS degenerative diseases likeAlzheimer's disease as well as peripheral neuropathies and otherdisorders of the central and peripheral nervous system. WO94/14780discloses certain structurally similar pyrimidine derivatives asneuronal nitric oxide synthase inhibitors.

SUMMARY OF THE INVENTION

We have now discovered a novel series of substituted 5-alkynylpyrimidines that demonstrate NGF-like activity and/or enhancement of NGFactivity in PC12 cells. The compounds stimulated both neurite outgrowthand choline acetyltransferase activity in in vitro experiments. Suchactivities are predictive for causing increased cholineacetyltransferase activity in rat striatum and improving cognitativeperformance in animal models of age-induced working memory deficits bypotentiating the activity of endogenous NGF in the brain. [see P. J.Middlemiss, A. J. Glasky, M. P. Rathbone, E. Werstuik, S. Hindley and J.Gysbers, AIT-082, A Unique Purine Derivative, Enhances Nerve GrowthFactor Mediated Neurite Outgrowth from PC-12 cells. Neuroscience Let.,199, 131 (1995); A. J. Glasky, C. L. Melchior, B. Pirzadeh, N. Heydariand R. F. Ritzmannn, Effect of AIT-082, a Purine Analog, on WorkingMemory in Normal and Aged Mice. Pharmacol. Biochem. Behav., 47, 325(1994); R. Morris, Developments of a Water-maze Procedure for StudyingSpatial Learning in the Rat. J. Neurosci. Methods, 11, 47 (1984)].

DETAILED DESCRIPTION OF THE INVENTION

According to the present invention, there are provided novel compoundsof Formula I:

-   -   wherein        -   Z is O, NH or S, and m is 0 or 1;        -   R₁ is (C2–6alkyl)_(a)(C3–10cycloalkyl, C2–9heterocycloalkyl,            C5–10aryl, or C4–9heteroaryl)_(b)(C1–6alkyl)_(c), wherein a,            b and c are independently 0 or 1, provided that at least one            of a, b and c is 1 and if b is 0, then c is also 0, and            wherein the hetero groups include an N, O or S atom and the            C and N atoms of R₁ may optionally be substituted with one            or more substituents selected from the group consisting of:    -   OH;    -   halogen:    -   thio;    -   oxo;    -   thioxo;    -   carboxy;    -   carboxamide;    -   C1–7alkylcarbonyl;    -   C1–7alkylcarbonyloxy    -   C1–7alkylthiocarbonyl;    -   C1–8alkyloxy;    -   hydroxyC2–8alkyloxy;    -   di-C1–8alkylphosphate ester    -   C1–8alkylthio;    -   hydroxyC2–8alkylthio;    -   C1–8alkylsulfinyl;    -   C1–8alkylsulfonyl;    -   C1–5alkyloxyC1–5alkyl;    -   C1–5alkylthioC1–5alkyl;    -   C1–5alkylsulfinylC1–5alkyl; and    -   C1–5alkylsulfonylC1–5alkyl;        -   R₂ is selected from the group consisting of H, NH₂ and            NH—CO—R₃, where R₃ is H or C1–12 alkyl;        -   X is C6–10aryl optionally substituted with one or more            substituents (y) selected from the group consisting of:    -   OH;    -   NO₂    -   NH₂    -   NH—CO—R₄ where R₄ is H, C1–12alkyl, aryl or (C1–6alkyl)aryl    -   halogen;    -   C1–6alkyl;    -   hydroxyC1–6alkyl;    -   oxoC2–7alkyl;    -   C2–7alkenyl;    -   C2–7alkynyl;    -   C1–6alkoxy;    -   CF₃;    -   CF₃C1–6alkyl;    -   OCF₃; and    -   CF₃C1–6alkoxy;        and pharmaceutically acceptable esters, amides, salts or        solvates thereof.

By “alkyl” is meant straight or branched chain alkyl. By“heterocycloalkyl” is meant a saturated ring containing 1 to 4heteroatoms selected from the group consisting of N, O and S. By “aryl”is meant an aromatic ring such as phenyl or naphthyl. By “heteroaryl” ismeant an aromatic ring containing 1 to 4 heteroatoms selected from thegroup consisting of N, O and S. By “halogen” is meant F, Cl, Br or I.

The present invention includes all enantiomeric and diastereomeric formsof the compounds of Formula I either individually or admixed in anyproportion.

The present invention further includes prodrugs and active metabolitesof the compounds of Formula I. A prodrug includes any compound which,when administered to a mammal, is converted in whole or in part to acompound of Formula I. As is well known in the pharmaceutical arts, aspecific drug compound may be utilized in its active form, or in theform of a “prodrug” which is converted to the active form (or to anactive metabolite) of the compound when administered to the patient. Inthe present invention, esters or amides of the compounds of Formula Iwhich are hydrolyzed in the body to form the compounds of Formula I areexamples of prodrugs of such compounds. An active metabolite is aphysiologically active compound which results from the metabolism of acompound of Formula I, or a prodrug thereof, when such compound orprodrug is administered to a mammal. It is well know that drugs aremetabolized by the body into a variety of derivative compounds, one ormore of which may be responsible in whole or in part for the recognizedactivity of the drug. Such metabolites of the drug constitute aninherent part of the underlying drugs of the present invention, but mustbe identified individually for each compound by blood analysis of thepatient. Such identification is well within the skill of the art and isroutinely practiced as a part of the clinical evaluation and regulatoryapproval process for commercial drug products. Accordingly, whilespecific metabolites cannot be identified herein for all the compoundsencompassed by the present invention, the identification of metabolitesfor any given compound is merely a routine undertaking once thatcompound has been selected for administration to a mammal. Prodrugs andactive metabolites of the compounds of the present invention, therefore,are an inherent part of the invention and intended to be included withinthe scope thereof.

Preferred compounds of Formula I are those wherein X is phenyl which isunsubstituted or substituted at the 4-position. Particularly preferredare those compounds wherein X is phenyl substituted with 4-chloro, 2,4dichloro, 4-bromo, 2-fluoro-4-chloro, 2-chloro-4-fluoro,2-methyl-4-chloro, 4-methyl, 4-ethyl or 4-acetamido. Also preferred arethose compounds wherein R₁ is an oxy or hydroxy substituted phenyl,phenylethyl, cyclohexyl, alkyl or alkoxyalkyl. Particularly preferredare those compounds where (Z)_(m)-R₁ is 4-oxocyclohexylamino,trans-4-hydroxy-cyclohexylamino, cis-4-hydroxycyclohexylamino,4-hydroxyanilino, 4-methoxyanilino, 3,4-dimethoxyanilino,4-hydroxypiperdino, 2-hydroxyethylamino or2-(2-hydroxyethoxy)ethyl-amino. Yet further preferred compounds ofFormula I are those where R₂ is NH₂ or formamido. The compounds ofFormula I above and their pharmaceutically acceptable salts or solvatesare sometimes hereinafter referred to as “compounds of the presentinvention”.

Preferred compounds of Formula I are more particularly defined accordingto the following Formulas IA–IC:

-   -   wherein p is 0, 1 or 2, and each y (which may be the same or        different), R₁ and R₂ are as hereinbefore defined;

-   -   wherein p is 0, 1 or 2, and each y (which may be the same or        different), R₁ and R₂ are as hereinbefore defined;

-   -   wherein p is 0, 1 or 2, and each y (which may be the same or        different), R₁ and R₂ are as hereinbefore defined.

Representative compounds of the present invention are:

-   2-Amino-5-(4-chlorophenylethynyl)-4-(4-acetylpiperazino)pyrimidine-   4-(trans-4-Hydroxycyclohexylamino)-5-phenylethynylpyrimidine-   4-[2-(2-Hydroxyethoxy)ethylamino]-5-phenylethynylpyrimidine-   5-(4-Chlorophenylethynyl)-4-[2-(2-hydroxyethoxy)ethylamino]pyrimidine-   2-Amino-5-(4-chlorophenylethynyl)4-[2-(2-hydroxyethoxy)ethylamino]pyrimidine-   4-[4-(2-Hydroxyethyl)piperazino]-5-phenylethynylpyrimidine-   2-Amino-4-[4-(2-hydroxyethyl)piperazino]-5-phenylethynylpyrimidine-   2-Amino-5-(4-chlorophenylethynyl)-4-[4-(2-hydroxyethyl)piperazino]pyrimidine-   4-(4-Hydroxypiperidino)-5-phenylethynylpyrimidine-   5-(4-Chlorophenylethynyl)-4-(4-hydroxypiperidino)pyrimidine-   2-Amino-4-(4-hydroxypiperidino)-5-phenylethynylpyrimidine-   2-Amino-5-(4-chlorophenylethynyl)-4-(4-hydroxypiperidino)pyrimidine-   4-(2-Hydroxyethylamino)-5-phenylethynylpyrimidine-   2-Amino-4-(2-hydroxyethylamino)-5-phenylethynylpyrimidine-   2-Amino-4-(4-hydroxyanilino)-5-phenylethynylpyrimidine-   2-Amino-4-(4-trans-hydroxycyclohexylamino)-5-(4-n-pentylphenylethynyl)    pyrimidine-   2-Acetamido-4-(4-trans-acetoxycyclohexylamino)-5-(4-chlorophenylethynyl)    pyrimidine-   2-Amino-5-(4-t-butylphenylethynyl)-4-(4-trans-hydroxycyclohexylamino)    pyrimidine-   2-Amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyphenylethylamino)pyrimidine-   2-Amino-4-(4-hydroxyanilino)-5-(4-methoxyphenylethynyl)pyrimidine-   2-Amino-5-(4-propylphenylethynyl)-4-(4-trans-hydroxycyclohexylamino)    pyrimidine-   2-Amino-4-(4-hydroxy-2-methylanilino)-5-(4-chlorophenylethynyl)pyrimidine-   2-Amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyanilino)pyrimidine-   2-Amino-5-(4-chlorophenylethynyl)-4-(4-oxocyclohexyloxo)pyrimidine-   2-amino-5-(4-chlorophenylethynyl)-4-[2-(2-hydroxyethoxy)ethoxy]pyrimidine-   2-amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyphenoxy)pyrimidine-   2-amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyphenylthio)pyrimidine,    and-   5-(4-chlorophenylethynyl)-2-formamido-4-(4-hydroxyphenylthio)pyrimidine    and the pharmaceutically acceptable esters, amides, salts or    solvates thereof.

Preferred compounds of the present invention are:

-   4-(4-Hydroxyanilino)-5-phenylethynylpyrimidine-   5-(4-Chlorophenylethynyl)-4-(4-hydroxyanilino)pyrimidine-   2-Amino-4-[2-(2-hydroxyethoxy)ethylamino]-5-(4-methylphenylethynyl)pyrimidine-   2-Amino-4-(trans-hydroxycyclohexylamino)-5-(4-methylphenylethynyl)pyrimidine-   5-(4-Chlorophenylethynyl)-2-formamido-4-(4-trans-hydroxycyclohexylamino)    pyrimidine-   2-Amino-5-(3,4-dichlorophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)    pyrimidine-   2-Amino-5-(4-chlorophenylethynyl)-4-(4-oxocyclohexylamino)pyrimidine-   2-Amino-5-(2-chlorophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)    pyrimidine-   2-Amino-5-(4-bromophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)    pyrimidine-   2-Amino-5-(4-chlorophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)    pyrimidine-O-dimethylphosphate ester-   2-Amino-5-(4-chlorophenylethynyl)-4-(3,4-dimethoxyanilino)pyrimidine-   5-(4-Acetamidophenylethynyl)-2-amino-4-(4-trans-hydroxycyclohexylamino)    pyrimidine    and the pharmaceutically acceptable esters, amides, salts or    solvates thereof.

Particularly preferred compounds of the present invention are:

-   5-(4-Chlorophenylethynyl)-4-(trans-4-hydroxycyclohexylamino)pyrimidine-   2-Amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyanilino)pyrimidine-   2-Amino-4-(trans-4-hydroxycyclohexylamino)-5-phenylethynylpyrimidine-   2-Amino-5-(4-chlorophenylethynyl)-4-(trans-4-hydroxycyclohexylamino)    pyrimidine-   2-Amino-5-(4-chlorophenylethynyl)-4-(cis-4-hydroxycyclohexylamino)pyrimidine-   2-Amino-4-[2-(2-hydroxyethoxy)ethylamino]-5-phenylethynylpyrimidine-   2-Amino-5-(4-chlorophenylethynyl)-4-(2-hydroxyethylamino)pyrimidine-   2-Amino-5-(4-ethylphenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine    and the pharmaceutically acceptable esters, amides, salts or    solvates thereof.

In one aspect of the invention, compounds of the present invention areprovided for use in medical therapy, particularly for the treatment ofneurodegenerative or neurological disorders of the central or peripheralnervous systems.

Examples of nervous system disorders which may be treated in accordancewith the invention include dementing disorders such as age-relatedsenility, senile dementia or Age Related Mental Impairment (ARMI),cerebal ataxia, Parkinson's disease, Alzheimer's disease, peripheralneuropathy, cognitive disorders secondary to stroke or trauma andattention-deficit hyperactivity disorder. In addition, nerve injuries,for example, spinal cord injuries, that require neuroregeneration mayalso be treated in accordance with the invention.

In another aspect of the invention, compounds of the present inventionare provided for use in the treatment of seizure disorders such asepilepsy.

In a further aspect of the invention, compounds of the present inventionare provided for use in the treatment of diabetes.

In a further aspect of the present invention there is included:

-   a) A method for the treatment of neurodegenerative or neurological    disorders of the central or peripheral nervous systems which    comprises treating the subject, e.g., a mammal, such as a human,    with a therapeutically effective amount of a compound of the present    invention;-   b) A method for the treatment of seizure disorders which comprises    treating the subject, e.g., a mammal such as a human, with a    therapeutically effective amount of a compound of the present    invention;-   c) A method for the treatment of diabetes which comprises treating    the subject, e.g., a mammal such as a human, with a therapeutically    effective amount of a compound of the present invention; and-   d) The use of a compound of the present invention in the manufacture    of a medicament for the treatment of any of the above mentioned    disorders.

In addition, since the compounds of the present invention have beenshown to enhance differentiation signals but not mitotic signals tocells in culture, the compounds can be used in clinical situations whereenhancement of differentiation signals would be of benefit to thepatient, as, for example, in the study of tumors derived from stem cellswhere the differentiation signals are overpowered by the mitoticsignals.

Examples of pharmaceutically acceptable salts of the compounds of thepresent invention include acid addition salts. However, salts ofnon-pharmaceutically acceptable acids may be of utility in thepreparation and purification of the compounds of the present invention.Preferred salts include those formed from hydrochloric, hydrobromic,sulfuric, phosphoric, citric, tartaric, lactic, pyruvic, acetic,succinic, fumaric, maleic, oxaloacetic, methanesulfonic, ethanesulfonic,p-toluenesulfonic, benzenesulfonic and isethionic acids.

Examples of pharmaceutically acceptable esters of the compounds of thepresent invention include straight chain or branched aliphatic esterssuch as the formyl, acetyl, n-butyl, isobutyl and t-butyl esters,aromatic or substituted aromatic esters such as the benzoyl, naphthoyland p-chlorobenzoyl esters, alkylaryl esters such as the phenylacetyl,naphthylacetyl and benzyl esters, and amino acid esters such as theL-valyl, L-isoleucyl and L-phenylalanyl esters. Many of these esters arehydrolysed to the compounds of Formula I upon administration to mammalsand accordingly constitute prodrugs of the compounds of Formula I.

The compounds of the present invention and pharmaceutically acceptableesters, amides, salts or solvates thereof may be employed in combinationwith other therapeutic agents for the treatment of the above disorders.Examples of such further therapeutic agents include COGNEX, ARICEPT andother agents (e.g., acetylcholine esterase inhibitors, muscarinic ornicotinic receptor agonists, MAO inhibitors) that are effective for thetreatment of neurodegenerative or neurological disorders of the centralor peripheral nervous systems. The component compounds of suchcombination therapy may be administered simultaneously in eitherseparate or combined formulations, or at different times, e.g.,sequentially such that a combined effect is achieved.

While it is possible for compounds of the present invention to beadministered as the raw chemical, it is preferable to present them as apharmaceutical formulation. The formulations of the present inventioncomprise a compound of Formula I, as above defined, or apharmaceutically acceptable ester, amide, salt or solvate thereof,together with one or more pharmaceutically acceptable carriers thereforand optionally other therapeutic ingredients. The carrier(s) must beacceptable in the sense of being compatible with the other ingredientsof the formulation and not deleterious to the recipient thereof.

The formulations include those suitable for oral, parenteral (includingsubcutaneous, transdermal, intradermal, intramuscular and intravenous),rectal and topical (including dermal, buccal and sublingual)administration although the most suitable route may depend upon, forexample, the condition and disorder of the recipient. The formulationsmay conveniently be presented in unit dosage form and may be prepared byany of the methods well know in the art of pharmacy. All methods includethe step of bringing into association a compound of Formula I or apharmaceutically acceptable salt, ester amide or solvate thereof (activeingredient) with the carrier which constitutes one or more accessoryingredients. In general the formulations are prepared by uniformly andintimately bringing into association the active ingredients with liquidcarriers or finely divided solid carriers or both and then, ifnecessary, shaping the product into the desired formulation.

Formulations of the present invention suitable for oral administrationmay be presented as discrete units such as capsules, cachets or tabletseach containing a predetermined amount of the active ingredient; as apowder or granules; as a solution or a suspension in an aqueous liquidor a non-aqueous liquid; or as an oil-in-water liquid emulsion, or awater-in-oil liquid emulsion. The active ingredient may also bepresented as a bolus, electuary or paste.

Formulations for parenteral administration include aqueous andnon-aqueous sterile injection solutions which may contain anti-oxidants,buffers, bacterioistats and solutes which render the formulationisotonic with the blood of the intended recipient; and aqueous andnon-aqueous sterile suspensions which may include suspending agents andthickening agents. The formulations may be presented in unit-dose ormulti-dose containers, for Example sealed ampoules and vials, and may bestored in a freeze-dried (lyophillised) condition requiring only theaddition of the sterile liquid carrier, for Example,water-for-injection, immediately prior to use. Extemporaneous injectionsolutions and suspensions may be prepared from sterile powders, granulesand tablets of the kind previously described.

Formulations suitable for transdermal administration may be presented asdiscrete patches adapted to remain in intimate contact with theepidermis of the recipient for a prolonged period of time. Such patchessuitably contain the active compound 1) in an optionally buffered,aqueous solution or 2) dissolved and/or dispersed in an adhesive or 3)dispersed in a polymer. A suitable concentration of the active compoundis about 1% to 35%, preferably about 3% to 15%. As one particularpossibility, the active compound may be delivered from the patch byelectrotransport or iontophoresis, as generally described inPharmaceutical. Res., 3(6), 318 (1986).

Preferred unit dosage formulations are those containing an effectivedose, as hereinbelow recited, or an appropriate fraction thereof, of theactive ingredient.

It should be understood that in addition to the ingredients particularlymentioned above, the formulations of this invention may include otheragents conventional in the art having regard to the type of formulationin question. For example, those suitable for oral administration mayinclude flavoring agents.

For the above-mentioned conditions and disorders, the compounds of theFormula I are preferably administered orally or by injection(intraparenteral or subcutaneous). The precise amount of compoundadministered to a patient will be the responsibility of the attendantphysician. However, the dose employed will depend on a number offactors, including the age and sex of the patient, the precise disorderbeing treated, and its severity. Also the route of administration islikely to vary depending on the condition and its severity.

In chronic dosing for each of the above-mentioned indications, thecompounds of Formula I may be administered orally by tablets or otherforms of presentation in discrete units which may contain from about 0.5mg to 500 mg and generally from about 1 mg to 250 mg of compound. Thetypical oral dose range for adult humans is from about 1 to 1000 mg/day,and generally from about 5 to 250 mg/day. The compounds of Formula I maybe administered by injection at a dose of from about 1 to 1000 mg/day,and generally from about 5 to 1000 mg/day. In clinical situations whereacute dosing is appropriate, higher doses of from two to ten times thechronic dose may be utilized.

The present invention further includes processes for the preparation ofcompounds of Formula I and esters, amides, salts or solvates thereof bythe methods hereinafter described, or in any manner known in the art forthe preparation of compounds of analogous structure.

Esters and amides of the compounds of the present invention can be madeby reaction with a carbonylating agent (e.g., ethyl formate, aceticanhydride, methoxyacetyl chloride, benzoyl chloride, methyl isocyanate,ethyl chloroformate, methanesulfonyl chloride) and a suitable base(e.g., 4-dimethylaminopyridine, pyridine, triethylamine, potassiumcarbonate) in a suitable organic solvent (e.g., tetrahydrofuran,acetone, methanol, pyridine, N,N-dimethylformamide) at a temperature of0° C. to 60° C., and preferably 20° C. to 30° C.

Salts of the compounds of Formula I can be made from the free base formby reaction with the appropriate acid.

The following examples are directed to the preparation of representativecompounds of the present invention and certain intermediates useful intheir preparation. The examples are presented for purposes ofillustration only and should not be construed as limiting the scope ofthe present invention.

EXAMPLE 1

Preparation of 5-iodoisocytosine

Sodium hydroxide pellets (12.72 g) were dissolved in deionized water(318 mL) in a 1 liter round bottom flask and 2-amino-4-hydroxypyrimidine(35.0 g) was added with stirring. After the solids dissolved, iodineflakes (79.95 g) were added in one portion and the mixture was heated to90–100° C. for approximately 2.5 hours. The mixture was filtered whilehot and the solid was washed liberally with water, rinsed with methanol,and dried under vacuum at 115° C. to give 5-iodoisocytosine: 72.5 g.

EXAMPLE 2

Preparation of4-chloro-2-diisopropylaminomethyleneamino-5-iodopyrimidine

A solution of 4.5 mL of oxalyl chloride in 35 mL of dichloromethane wasadded dropwise over 25 minutes to an ice water bath-cooled solution of7.0 mL of N,N-diisopropylformamide in 65 mL of dichloromethane withmagnetic stirring. After a few minutes, 4.74 g of2-amino-4-hydroxy-5-iodopyrimidine was added in one portion. The bathwas removed and the solution was stirred at room temperature for 30minutes, then refluxed for one and one half hours. The solution wascooled and poured into an equal amount of ice-cold saturated aqueoussodium bicarbonate with stirring. The two phases were partitioned andthe organic layer washed with additional bicarbonate(2×), water(1×) andfinally saturated aqueous brine. After drying over sodium sulfate andfiltration, the solution was evaporated in vacuo to yield 10.13 g of areddish oil. The oil was purified by column chromatography on silicagel, eluting with dichloromethane. Like fractions were pooled,evaporated and triturated with hexanes to give white free flowingcrystals, 5.94 g, m.p. 97–100° C.

EXAMPLE 3

Preparation of 4-chloro-5-(4-chlorophenylethynyl)pyrimidine

A mixture of 0.6 g of 1-chloro-4-ethynylbenzene, 1.44 g of4-chloro-5-iodopyrimidine (J. Chem. Soc. Perkins Trans. I, 1977,621,Allen et al), 7.0 cc of triethylamine, 58 mg of copper iodide and 108 mgof dichlorobis(triphenylphosphine)palladium II was stirred at roomtemperature under nitrogen for 18 hours. The reaction mixture wasevaporated in vacuo. The resulting tan solid was partitioned betweenwater and dichloromethane and the organic extracts washed twice withwater, dried over sodium sulfate and evaporated to give a dark brownsolid, 1.57 g. The solid was redissolved in dichloromethane and hexanesadded to give 120 mg of a beige powder after filtration. The filtratewas purified by column chromatography on silica gel using 1:1 ethylacetate/dichloromethane as the eluant. The middle rf spot fractions(silica gel TLC in 1:1) were pooled and evaporated to give 0.8 g of ayellow solid, 4-chloro-5-(4-chlorophenylethynyl)-pyrimidine

EXAMPLE 4

Preparation of5-(4-chlorophenylethynyl)-4-(trans-4-hydroxycyclohexylamino) pyrimidine

A mixture of 0.46 g of 4-chloro-5-(4-chlorophenylethynyl)pyrimidine, 3.0mL of dichloromethane, 3.0 mL of acetonitrile, 1.7 mL of triethylamineand 0.92 g of trans-4-aminocyclohexanol hydrochloride was refluxed for18 hours. The mixture was evaporated in vacuo and partitioned betweendichloromethane and water. The organic phase was washed an additionaltime with water, dried over sodium sulfate, filtered and evaporated togive 0.54 g of a yellow foam. It was dissolved in dichloromethane andapplied to a column of fine mesh silica gel in the same solvent. Thecolumn was eluted with 1:1 ethyl acetate/dichloromethane, then theproduct was eluted with ethyl acetate to yield, after evaporation, 0.53g of a brittle foam. An aliquot was triturated with ether to give thedesired product5-(4-chlorophenylethynyl)-4-(trans-4-hydroxycyclohexylamino)pyrimidineas a 0.2 M hydrate, m.p. 151–155° C.

EXAMPLE 5

Preparation of 4-chloro-5-phenylethynylpyrimidine

A mixture of 2.1 g of 4-chloro-5-iodopyrimidine, 10 mL of triethylamine,1.2 mL phenylacetylene, 80 mg copper iodide and 160 mg ofdichlorobis(triphenylphosphine was stirred at room temperature for 18hours. The mixture was diluted with dichloromethane and evaporated invacuo. The residue was redissolved in a few mL of dichloromethane, 10 mLof triethylamine added and the mixture heated at reflux for one hour.The heterogeneous mixture was evaporated in vacuo and the residueobtained was partitioned between water and dichloromethane. A gelatinousprecipitate which formed on shaking the two layers was filtered off,enabling separation of the two layers. The organic extracts were driedover sodium sulfate, filtrated and evaporated in vacuo to yield 2.5 g ofa dark brown syrup. The syrup was purified by column chromatography onsilica gel, twice, eluting with hexanes, 1:1 hexanes/dichloromethane,dichloromethane and finally ethyl acetate. Like fractions fromdichloromethane elution were pooled, obtaining 350 mg of the product,5-phenylethynyl-4-chloropyrimidine as an oil which solidified to whiterosettes.

EXAMPLE 6

Preparation of4-(trans-4-hydroxycyclohexylamino)-5-phenylethynylpyrimidine

A mixture of 0.2 g of 5-phenylethynyl-4-chloropyrimidine, 10 mL ofacetonitrile, 0.42 g of trans aminocyclohexanol and 0.4 mL oftriethylamine was refluxed overnight with magnetic stirring. The mixturewas cooled and filtered and the filtrate evaporated in vacuo. Theresidue was purified by column chromatography on silica gel, elutingsuccessively with dichloromethane, 1:1 dichloromethane and finally ethylacetate. The product,4-(trans-4-hydroxycyclohexylamino)-5-phenylethynylpyrimidine, 200 mg,was obtained on evaporation of the latter eluate.

EXAMPLE 7

Preparation of4-chloro-2-diisopropylaminomethyleneamino-5-phenylethynylpyrimidine

A mixture of 2.46 g4-chloro-2-diisopropylaminomethyleneamino-5-iodopyrimidine, 7.5 mLtriethylamine, 0.064 g copper iodide, 0.12 gdichlorobis(triphenyl)phosphine palladium II and 0.9 mL phenylacetylenewas stirred under nitrogen at room temperature for two days. The darkbrown mixture was evaporated in vacuo at a bath temperature of 30–35° C.The residue was partitioned between dichloromethane and water. Theorganic phase was washed thrice with water, dried over sodium sulfate,filtered and evaporated to yield 3.37 g of a dark brown oil. The residuewas dissolved in hexanes and purified by column chromatography on silicagel, eluting successively with hexanes, 1:1 dichloromethane/hexanes anddichloromethane. The product was obtained from the latter eluant toyield after evaporation, 1.69 (74%) g of4-chloro-2-diisopropylaminomethyleneamino-5-phenylethynylpyrimidine.

EXAMPLE 8

Preparation of2-diisopropylaminomethyleneamino-4-(trans-4-hydroxycyclohexylamino-5-phenylethynylpyrimidine

A mixture of 0.5 g of4-chloro-2-diisopropylaminomethyleneamino-5-phenylethynylpyrimidine, 15mL of acetonitrile, 0.67 g of trans 4-aminocyclohexanol hydrochlorideand 1.8 mL of triethylamine was refluxed with magnetic stirring 18hours. The mixture was chilled, filtered and the precipitate washed withacetonitrile. The filtrate was evaporated in vacuo and the resultingrust colored residue dissolved in dichloromethane. The solution wasloaded on a column of fine mesh silica gel. The column was eluted withdichloromethane, then successively with 10%, 30%, 60% ethyl acetate indichloromethane, ethyl acetate and finally 10% methanol indichloromethane. Recovered starting material,4-chloro-2-diisopropylaminomethyleneamino-5-phenylethynylpyrimidine,0.180 g was obtained on evaporation of the 10% ethyl acetate eluate. Theproduct,2-diisopropylaminomethyleneamino-4-trans-4-hydroxycyclohexylamino-5-phenylethynylpyrimidine,0.32 g, was obtained from evaporation of the 60% and subsequent eluates.

EXAMPLE 9

Preparation of2-amino-4-(trans-4-hydroxycyclohexylamino)-5-phenylethynylpyrimidine

A solution of 0.24 g of2-diisopropylaminomethyleneamino-4-(trans-4-hydroxycyclohexylamino-5-phenylethynyl-pyrimidinein 5.0 mL each of ethanol and 4% aqueous sodium hydroxide was refluxedfor 18 hours. The solution was evaporated in vacuo and the residueextracted with dichloromethane. The extracts were washed with water anddried over sodium sulfate. The filtered solution was loaded on a columnof fine mesh silica gel in the same solvent. After washing the columnwith dichloromethane and acetonitrile, the product was eluted with 5%and 10% methanol in dichloromethane, to obtain on evaporation 0.1 g of abrittle foam. The product was converted to the hydrochloride by additionof ethanolic HCl to a solution of the base in 1:1 ether-ethanol to a pHof 2.0. The resulting solution was evaporated in vacuo and trituratedwith acetone and dried to yield 0.063 g of a yellow solid, one spot byTLC (10% methanol in dichloromethane).

EXAMPLE 10

Preparation of4-chloro-5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneamino-pyrimidine

A mixture of 0.722 g4-chloro-2-diisopropylaminomethyleneamino-5-iodopyrimidine, 3.5 mLtriethylamine, 0.025 g copper iodide, 0.037 gdichlorobis(triphenyl)phosphine palladium II and 0.289 g1-chloro-4-ethynylbenzene was stirred under nitrogen at room temperaturefor 18 hours. The dark brown mixture was evaporated in vacuo at a bathtemperature of 30–35° C. The beige residue was partitioned betweendichloromethane and water. The organic phase was washed twice withwater, dried over sodium sulfate, filtered and evaporated to yield 1.0 gof a caramel colored film. The residue was dissolved in 1:1dichloromethane/hexanes and purified by column chromatography on silicagel, eluting successively with 1:1 dichloromethane/hexanes,dichloromethane and ethyl acetate. The product was recovered from thelatter two eluates by evaporation to yield 0.7 g of4-chloro-5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneaminopyrimidine.

EXAMPLE 11

Preparation of5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneamino-4-(trans-4-hydroxycyclohexylamino)pyrimidine

A mixture of 0.46 g of4-chloro-5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneamino-pyrimidine,15 mL of acetonitrile, 2 mL of triethylamine and 0.56 g oftrans-4-aminocyclohexanol hydrochloride was refluxed 18 hours withmagnetic stirring. The mixture was chilled, filtered and the precipitatewashed with acetonitrile. The filtrate was evaporated in vacuo and theresulting rust colored residue dissolved in dichloromethane. Thesolution was loaded on a column of fine mesh silica gel. The column waseluted with dichloromethane, yielding 0.19 g of starting material,5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneamino-4-chloropyrimidine,with ethyl acetate and finally 10% methanol in dichloromethane to give0.53 g of5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneamino-4-(trans-4-hydroxycyclohexylamino)-pyrimidine.The ¹H NMR spectrum (CDCl3) was consistent with the structure.

EXAMPLE 12

Preparation of2-amino-5-(4-chlorophenylethynyl)-4-(trans-4-hydroxycyclohexylamino)pyrimidine

A mixture of 1.25 g of4-chloro-5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneamino-pyrimidine,33 mL of ethanol, 2.02 g of trans-4-aminohexanol hydrochloride and 1.9mL of triethylamine was stirred at reflux for three days. The clearamber solution was evaporated in vacuo and the beige solid waspartitioned between dichloromethane and water. A portion of the solidinsoluble in either phase was filtered off. It weighed 0.24 g and wasidentical on TLC(silica gel in ethyl acetate) to the product obtainedfrom the organic phase. The organic phase was dried over sodium sulfate,filtered and evaporated in vacuo to give 0.67 g. Purification of thelatter by column chromatography on silica gel was effected by firsteluting the column with dichloromethane and 50% ethyl acetate indichloromethane. Elution with ethyl acetate and evaporation yielded 190mg of the desired product,2-amino-5-(4-chlorophenylethynyl)-4-(trans-4-hydroxycyclohexylamino)pyrimidine.An analytical sample was obtained by recrystallization of the materialfiltered from the reaction from 2-propanol and water, 0.19 g. m.p.215–218° C.,

EXAMPLE 13

Preparation of 2-amino-5-(4-chlorophenylethynyl)-4-(2-hyroxyethylamino)pyrimidine

A mixture of 0.7 g of4-chloro-5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneamino-pyrimidine,20 mL ethanol and 0.6 mL ethanolamine was refluxed for 18 hours. Thegreen solution was evaporated in vacuo and triturated with water. Theinsoluble yellow residue was recrystallized by dissolving in 35 mL hotmethanol, concentrating to 10 mL and chilling. The pale yellow powderyprecipitate was filtered and dried to yield 0.34 g of2-amino-5-(4-chlorophenylethynyl)-4-(2-hyroxyethylamino)pyrimidine, m.p.197–200° C.

EXAMPLE 14

Preparation of2-amino-5-(4-chlorophenylethynyl)-4-[2-(2-hydroxyethoxy)ethylamino]pyrimidine

A mixture of 0.3 g of4-chloro-5-(4-chlorophenyl)-ethynyl-2-diisopropylaminomethyleneamino-pyrimidine,6.0 mL ethanol and 0.26 g of 2-(2-aminoethyoxy)ethanol was refluxed for18 hours. The reaction mixture was evaporated in vacuo, the yellow soliddissolved in dichloromethane and loaded on a column of silica gel in thesame solvent. The column was eluted successively with dichloromethane,5% and 10% methanol/dichloromethane. The product 0.15 g was obtainedfrom evaporation of the 10% eluate as a pale yellow solid.Recrystallization from boiling methanol gave 0.17 g of2-amino-5-(4-chlorophenylethynyl)-4-[2-(2-hydroxyethoxy]ethylamino]pyrimidine.m.p. 176–180° C.

EXAMPLE 15

Preparation of 4-(4-acetylpiperazino)-2-amino-5-(4-chlorophenylethynyl)pyrimidine

A mixture of 0.8 g of4-chloro-5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneamino-pyrimidine,35 mL acetonitrile and 0.71 g 1-acetyl piperazine was refluxed for oneand one half hours. A green solution initially forms and the colorchanges to amber on continued heating. The solution was evaporated invacuo and partitioned between dichloromethane and water. The organicphase was washed twice with water, dried over sodium sulfate, filteredand evaporated. The orange-brown brittle foam obtained was purified bycolumn chromatography on silica gel, eluting initially withdichloromethane and then with 15% methanol/dichloromethane to give theintermediate derivative, 4-(-4-acetylpiperazino)-5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneaminopyrimidine.Heating 0.6 g of the intermediate with 40 mL methanolic ammonia in abomb at 120° C. for 18 hours gave on evaporation in vacuo, acocoa-colored residue which was purified by column chromatography onsilica gel. The desired product4-(4-acetylpiperazino)-2-amino-5-(4-chlorophenylethynyl)pyrimidine wasobtained by elution with 5% methanol/dichloromethane, evaporation andtrituration with methanol yielding 0.27 g, m.p. 165° C.

EXAMPLE 16

Preparation of2-amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyanilino)pyrimidine

A mixture of 0.932 mM of5-(4-Chlorophenylethynyl)-2-diisopropylaminomethyleneamino-4-chloropyrimidineand 0.102 g of 4-aminophenol in 5 mL ethanol was stirred at roomtemperature for four days.

The brown solution was evaporated in vacuo (bath temperature 30° C.) toobtain a brownish-burgundy solid. The residue was stirred indichloromethane and filtered to yield 0.4 g of5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneamino-4-(4-hydroxyanilino)pyrimidine.The ¹H NMR spectrum (CDCL₃) was consistent with this structure. Amixture of 0.37 g of this product was heated in a bomb with 32 mL ofmethanolic ammonia at a temperature of 100° C. for five hours. Thecooled bomb contents were evaporated in vacuo and triturated with icecold water and dried to yield a mixture of the desired2-amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyanilino)pyrimidine with2,4-diamino-5-(4-chlorophenylethynyl)pyrimidine.

EXAMPLE 17

Preparation of5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneamino-4-morpholinopyrimidine

A mixture of 0.46 g of4-chloro-2-diisopropylaminomethyleneamino-5-(4-chlorophenylethynyl)-pyrimidine,40 mL of acetonitrile and 0.41 g of morpholine was stirred at roomtemperature for 18 hours. The mixture was evaporated in vacuo and theresidue partitioned between water and dichloromethane. The organic layerwas washed once more with water, dried over sodium sulfate and filtered.The filtrate was loaded on a column of silica gel equilibrated in thesame solvent. After elution of an unknown impurity, the product elutedas a yellow band. Additional material was obtained by a final elutionwith 1:1 dichloromethane and ethyl acetate. Like fractions of the twoeluants were pooled and evaporated to give 0.63 g of a yellow oil,5-(4-Chlorophenylethynyl)-2-diisopropylaminomethyleneamino-4-morpholinopyrimidine.

EXAMPLE 18

Preparation of 2-amino-5-(4-chlorophenylethynyl)-4-morpholinopyrimidine

A solution of 0.63 g of5-(4-chlorophenylethynyl)-2-diisopropylaminomethyleneamino-4-morpholinopyrimidineand 35 mL of freshly prepared saturated methanolic ammonia was heated ina bomb at 60° C. for 18 hours. The bomb was cooled, opened and theyellow solution was cooled. A precipitate formed which was filtered togive 0.2 g of a yellow solid. Thin layer chromatography (silica gel in20% ethyl acetate in dichloromethane) showed the filtrate displayed twospots, the upper one corresponding to the starting material and thelower to the precipitate. The latter was homogeneous and its ¹H-NMR(DMSO-d₆) was consistent with the desired product,2-amino-5-(4-chlorophenylethynyl)-4-morpholinopyrimidine. The filtratewas evaporated and recharged with methanolic ammonia in a bomb at 80° C.for 18 hours. After a similar workup, an additional crop, 0.16 g of2-amino-5-(4-chlorophenylethynyl)-4-morpholinopyrimidine was obtained.Analytical samples as lustrous champagne colored flakes were obtained byrecrystallization from boiling MeOH, m.p. 193–194° C.

EXAMPLE 19

Preparation of 2-amino-4-[2-(2-hydroxyethoxy)ethylamino]-5-phenylethynylpyrimidine

A mixture of 1.5 g of4-chloro-2-diisopropylaminomethyleneamino-5-phenylethynylpyrimidine, 20mL of ethanol and 1.83 g of 2-(2-aminoethoxy)ethanol was refluxed for 18hours. The tea colored solution was evaporated in vacuo and the residuepartitioned between water and dichloromethane. The aqueous layer waswashed twice more with dichloromethane and the combined organic extractswashed with water. The organic solution was dried over sodium sulfate,filtered and evaporated in vacuo. The yellow residue obtained wastriturated with ether and filtered to give 0.49 g of a yellow solid,2-amino-4-[2-(2-hydroxyethoxy)ethylamino]-5-phenylethynylpyrimidine.m.p. 128–129° C.

EXAMPLE 20

Preparation of 4-(4-hydroxyanilino)-5-phenylethynylpyrimidinehydrochloride

A mixture of 0.23 g of 4-chloro-5-(4-phenylethynyl)pyrimidine, 8 mL ofethanol and 0.12 g of 4-hydroxyaniline was stirred at room temperaturefor 18 hours. The heterogeneous mixture was filtered, washed with etherand dried to yield 0.189 g of a yellow powder4-(4-hydroxyanilino)-5-phenylethynylpyrimidine hydrochloride, m.p.223–225° C., with decomposition.

EXAMPLE 21

Preparation of 5-(4-chlorophenylethynyl)-4-(4-hydroxyanilino)pyrimidinehydrochloride

A mixture of 0.28 g of 4-chloro-5-(4-Chlorophenylethynyl)pyrimidine, 10mL of ethanol and 0.14 g of 4-hydroxyaniline was stirred at roomtemperature for 18 hours. The black mixture was evaporated in vacuo andthe residue was triturated with dichloromethane, ethylacetate andacetonitrile. The combined organic extracts were absorbed on silica geland evaporated in vacuo. The powder was added to a column of silica gelequilibrated in dichloromethane and eluted with the same solvent. Thecolumn was eluted with ethyl acetate and then 10% methanol indichloromethane. These eluates on evaporation produced 100 mg of the5-(4-chlorophenylethynyl)-4-(4-hydroxyanilino)pyrimidine hydrochlorideas a muddy yellow powder.

EXAMPLE 22

Preparation of2-amino-5-(4-chlorophenylethynyl)-4-(4-oxocyclohexylamino) pyrimidine

Oxalyl chloride (1.52 g) and dichloromethane (50 mL) were combined undera nitrogen atmosphere and cooled to −78° C. in a dry ice-acetone bath.Dimethyl sulfoxide (1.88 g) was added dropwise via syringe through arubber septum cap. After completion of the addition, solid2-amino-5-(4-chlorophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine(3.43 g) was added in one portion and the mixture was stirred for 30minutes. Triethylamine (7 mL) was added in portions via syringe andafter completion of the addition the cooling bath was removed and themixture was allowed to warm to room temperature. The mixture was pouredinto water (40 mL) and the organic phase was separated; it was washedwith water (1×50 mL), brine (1×50 mL), dried over sodium sulfate,filtered and stripped in vacuo to a yellow foam. The product waspurified by chromatography on silica gel (30 g) using a mixture ofdichloromethane and ethyl acetate. Fractions corresponding to thedesired product were pooled and stripped in vacuo to give2-amino-5-(4-chlorophenylethynyl)-4-(4-oxocylohexylamino)pyrimidine as ayellow powder: 2.32 g; m.p. 176–178C.

EXAMPLE 23

Preparation of2-amino-5-(4-chlorophenylethynyl)-4-(4-cis-hydroxycyclohexylamino)pyrimidine

2-Amino-5-(4-chlorophenylethynyl)-4-(4-oxocyclohexylamino)pyrimidine(1.02 g) was dissolved in sodium dried tetrahydrofuran (100 mL) under anitrogen atmosphere and the mixture was cooled to −78° C. in a dryice-acetone bath. Lithium tri-sec-butylborohydride (6 mL, 1.0 mM in THF)was added via syringe through a rubber septum cap and the mixture wasstirred for 1.5 hours. The reaction mixture was quenched by addition ofsaturated aqueous ammonium chloride solution (8 mL) at −78° C. and thenwarmed to approximately 10–15° C. and decanted from the white solidswhich had formed. The solids were washed with dichloromethane and thecombined filtrates were stripped in vacuo and redissolved indichloromethane. The solution was washed with 2 M sodium hydroxide (1×50mL), brine (1×50 mL), dried over sodium sulfate, filtered and strippedin vacuo to a foam. The cis/trans mixture of amino alcohols was purifiedby chromatography on silica gel (10 g) using methylenechloride/acetoneas eluent. Fractions containing the cis-amino alcohol by tic were pooledand stripped in vacuo and the residue was crystallized from 95% aqueousethanol to give2-amino-5-(4-chlorophenylethynyl)-4-(4-cis-hydroxycyclohexylamino)pyrimidineas light yellow plates; 458.4 mg; m.p. 186–187° C.

EXAMPLE 24

Preparation of 4-ethyl-1-ethynylbenzene

A mixture of 5.6 mL of 1-ethyl-4-iodobenzene, 75 mL of triethylamine, 6mL of trimethylsilylacetylene, 0.49 g of dichlorotriphenylphosphinepalladium II and 0.314 g copper iodide was magnetically stirred atambient temperature for 18 hrs. The thick dark brown mixture wasfiltered, washing the gray precipitate with hexanes. The filtrate andwashings were evaporated in vacuo and the residue dissolved in hexanes.This solution was 96.7% pure by GC analysis. The solution was passeddown a column of silica gel which had been equilibrated in the samesolvent and the eluates evaporated in vacuo to yield 9.3 g of4-ethyl-1-trimethylsilyl ethynylbenzene as a dark amber liquid.

The residue was dissolved in 50 mL of methanol and stirred with 0.55 gof potassium carbonate at room temperature for 2.5 hrs. The mixture wasevaporated in vacuo with the bath temperature at 60° C. The resultingdark residue was partitioned between dichloromethane and water, theorganic phase washed with 0.1N aqueous HCl and filtered off some sludgefrom the organic phase. The extracts were dried over sodium sulfate,filtered and flash evaporated to give a dark brown liquid. The liquidwas stirred in hexanes, filtered and loaded on a column of silica gel inhexanes. Elution with this solvent gave a colorless solution, which onflash evaporation gave 3.44 g of 4-ethyl-1-ethynylbenzene as a paleyellow liquid, GC purity 99.4%.

EXAMPLE 25

Preparation of4-chloro-2-diisopropylaminomethyleneamino-5-(4-ethylphenylethynyl)pyrimidine

A mixture of 6.3 g of4-chloro-2-diisopropylaminomethyleneamino-5-iodopyrimidine, 33 mL oftriethylamine, 2.43 g of 4-ethyl-1-ethynylbenzene, 0.304 g ofdichlorobis(triphenyl)phosphine palladium II and 0.21 g copper iodidewas magnetically stirred at reflux temperature for 1.5 hrs. The mixturewas filtered and the filtrate evaporated in vacuo. Both the precipitateand the evaporated filtrate were dissolved in dichloromethane and washedwith water, dried over sodium sulfate, filtered and evaporated. Theresidues were dissolved in 1:1 dichloromethane-hexanes and separatelypurified by column chromatography. After initial elution with 1:1dichloromethane-hexanes, the product was obtained by elution withdichloromethane and 50% ethyl acetate-dichloromethane. Evaporation ofthe eluates gave 4.04 g of4-chloro-2-diisopropylaminomethyleneamino-5-(4-ethylphenylethynyl)pyrimidineas a thick amber syrup.

EXAMPLE 26

Preparation of2-amino-5-(4-ethylphenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine hydrochloride

A mixture of 1.925 mM of4-chloro-2-diisopropylaminomethyleneamino-5-(4-ethylphenyl)ethynylpyrimidine and 0.89 g of trans 4-aminocyclohexanol in 5.0 mL ofabsolute ethanol was heated in a bomb at 120° C. for 18 hours. Afterremoval, the dark amber bomb solution was evaporated in vacuo andco-evaporated with acetone. The residue was washed with water and thewater insoluble material flash evaporated with acetone. The residue wasdissolved in 5% methanol in dichloromethane and applied to a column ofsilica gel in the same solvent. Evaporation of the 5% eluates provided600 mg of a tan solid which was dissolved in ethanol and acidified withEtOAc-HCl to a pH of 1.0. Addition of excess ether and chilling gave0.21 g of2-amino-5-(4-ethylphenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidinehydrochloride. m.p. 240–255° C.

EXAMPLE 27

Preparation of5-(4-bromophenylethynyl)-4-chloro-2-diisopropylaminomethyleneaminopyrimidine

A mixture of 0.5 g of 1-bromo-4-ethynylbenzene, 5.0 mL of triethylamine,0.031 mg of copper iodide, 0.94 g of4-chloro-2-diisopropylaminomethyleneamino-5-iodopyrimidine and 0.046 gof dichlorobis(triphenyl)phosphine palladium II was magnetically stirredat room temperature for 18 hrs. The mixture was diluted withacetonitrile, filtered and the filtrate evaporated in vacuo. Theevaporated filtrate was dissolved in dichloromethane and loaded on acolumn of silica gel equilibrated in the same solvent. Cuts weremonitored by thin layer chromatography. After initial cuts of browncolored eluates, the product subsequently eluted as yellow fractions.Like cuts were pooled and evaporated to give 0.84 g of5-(4-bromophenylethynyl)-4-chloro-2-diisopropylaminomethyleneaminopyrimidineas a thick amber syrup.

EXAMPLE 28

Preparation of2-amino-5-(4-bromophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidinehydrochloride

5 A mixture of 1.3 g of5-(4-bromophenylethynyl)-4-chloro-2-diisopropylaminomethyleneamino-pyrimidineand 1.48 g of trans 4-amino-cyclohexanol in 16 mL of absolute ethanolwas refluxed for 18 hrs. The solvent was distilled off at atmosphericpressure and the residue cooled and triturated with water. The waterinsoluble residue was dissolved in methanol and azeotropically dried byco-evaporation (flash) with acetone. The olive green residue wasdissolved in methanol, preabsorbed on silica gel, evaporated and appliedto a column of silica gel equilibrated in ethyl acetate. The product waseluted with ethyl acetate and evaporated to give a pale green foamyresidue, 0.74 g of 2-amino-5-(4-bromophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine The solid was recrystallized from a minimumamount of boiling ethanol and chilled. A small amount of precipitate wasobtained (80 mg) of an unknown substance, which was different by TLCfrom the filtrate. The pH of the filtrate was adjusted to 2.0 with HClin EtOAC and the solution evaporated in vacuo to give a yellow solid.The solid was triturated with ether and filtered to give 0.69 g of abuttermilk powder. The solid was triturated with water to remove anyamine hydrochloride, then dried. The material, 0.23 g analyzed as theanhydrous salt2-amino-5-(4-bromophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidinehydrochloride, m.p 240° C. with decomposition.

EXAMPLE 29

Preparation of 1-acetamido-4-ethynylbenzene

A mixture of 1.0 g of 4-ethynylaniline and 2.4 mL of acetic anhydride in5.0 mL of dichloromethane was stirred at room temperature for 18 hours.The solution was evaporated in vacuo at 40° C. The resulting semi solidmixture was suspended in hexanes and filtered. The hexanes filtrate waswashed twice with water and dried over sodium sulfate. After filteringit was combined with the hexanes insoluble residue, dissolved indichloromethane and purified by column chromatography in the samesolvent to yield 0.96 g of 1-acetamido-4-ethynylbenzene.

EXAMPLE 30

Preparation of5-(4-acetamidophenylethynyl)-4-chloro-2-diisopropylaminomethyleneamino-pyrimidine

The compound was prepared following the general method of Example 27with the addition of acetonitrile as a reaction solvent.

Example 31

Preparation of5-(4-acetamidophenylethynyl)-2-amino-4-(4-trans-hydroxycyclohexylamino)-pyrimidinehydrochloride

The compound was prepared following the general method of Example 28.m.p. 238–245° C. with decomposition.

EXAMPLE 32

Preparation of 4-chloro-2-dimethylaminomethyleneamino-5-iodopyrimidine

N,N-dimethylformamide (54.1 g) and dry acetonitrile (500 mL) werecombined under nitrogen in a 4 liter round bottom flask. Oxalyl chloride(93.9 g) was added dropwise over a 1 hour period to form theintermediate Vilsmeier reagent and the HCl was vented through an aqueoussodium hydroxide scrubber. Solid 5-iodoisocytosine (77 g, 0.32 moles)was added in one portion and the mixture was heated at 60° C. forapproximately 3 hours. The mixture was cooled to about 25° C. and thesolids were filtered and washed with acetonitrile. The filter cake wasslurried with deionized water (500 mL) and sodium bicarbonate (29 g) wasadded to maintain pH 8. The solids were filtered, washed with water, anddried in vacuo at 50° C. to give4-chloro-2-dimethylaminomethyleneamino-5-iodopyrimidine: 88 g m.p.99–100° C.

EXAMPLE 33

Preparation of4-chloro-5-(4-chlorophenylethynyl)-2-dimethylaminomethyleneaminopyrimidine

A 1-liter, 3-neck-round-bottom flask was equipped with an air stirrer,reflux condenser, and a nitrogen inlet. The4-chloro-2-(dimethylaminomethyleneamino)-5-iodopyrimidine (65.2 g),ethanol (84 mL), and triethylamine (336 mL) were charged and heated toreflux. Copper (I) iodide (105 mg) and dichlorobis(triphenyl)phosphinepalladium II (386 mg) were added. Neat 1-chloro-4-ethynylbenzene (30.1g) was added and the mixture was refluxed approximately 2.5 hours. Themixture was cooled to ambient temperature, stirred for 1.5 hours andfiltered. The filter cake was slurried in water:ethanol (4:1 v/v, 120mL), filtered and dried in vacuo at 50° C. to give4-chloro-5-(4-chlorophenylethynyl)-2-dimethylaminomethyleneaminopyrimidineas a yellow solid: 55.7 g m.p. 195–197° C.

EXAMPLE 34

Preparation of 4-chloro-5-(4-chlorophenylethynyl)-2-formamidopyrimidine

4-Chloro-5-(4-chlorophenylethynyl)-2-dimethylaminomethyleneaminopyrimidine(65.1 g), isopropanol (585 mL), and water (36 mL) were combined andwarmed to 60° C. Methane sulfonic acid (23.1 g) was added and heating at60oC was continued for 1.5–2.0 hours or until HPLC analysis confirmedthe absence of the starting material. The mixture was cooled to ambienttemperature and held for 1.5 hours. The solids were removed byfiltration and washed with isopropanol (100 mL). The filter cake wasslurried in water (500 mL), basified with 1 N NaOH to pH 11, filtered,and the solids were rinsed with water. Vacuum drying at 50° C. providedpredominantly 4-chloro-5-(4-chlorophenylethynyl)-2-formamidopyrimidine:51.6 g.

EXAMPLE 35

Preparation of2-amino-5-(4-chlorophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine

4-Chloro-5-(4-chlorophenylethynyl)-2-formamidopyrimidine (42.9 g),n-propanol (344 mL), and trans-4-aminocyclohexanol (51.7 g) werecombined and heated to reflux. HPLC analysis confirmed that the reactionwas complete in approximately 4 hours. The mixture was cooled and heldat ambient temperature for 1.5 hours and the yellow solids were filteredand washed with ethanol (200 mL). The filter cake was slurried in water(250 mL), adjusted to pH 10 with 1N NaOH, and filtered. The filter cakewas washed with water (200 mL) and dried in vacuo at 50° C. to give2-amino-5-(4-chlorophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine:41.2 g m.p. 216–218° C.

EXAMPLE 36

Preparation of2-amino-4-(4-trans-hydroxycyclohexylamino)-5-(4-nitrophenylethynyl)pyrimidinehydrochloride

The compound was prepared in two steps by the methods of example 17 (atreflux temperature, 3.5 hrs) and example 12 (using four equivalents ofthe free base of 4-trans hydroxycyclohexylamine, in refluxingn-propanol, 18 hrs). m.p. 255° C.

EXAMPLE 37

Preparation of2-amino-4-(4-trans-hydroxycyclohexylamino)-5-(4-propylphenylethynyl)pyrimidinehydrochloride

A mixture of 5.0 g of 4-bromopropylbenzene, 15 mL of dichloromethane,0.64 g of copper iodide, 0.32 g of dichlorobis(triphenyl)phosphinepalladium II, 3.7 mL of trimethylsilylacetylene and 12.3 mL oftriethylamine was refluxed for 18 hrs. The mixture was evaporated invacuo (bath temperature 48° C.). The dark residue was dissolved inhexanes and passed through a pad of silica gel, washing the column wellwith additional solvent. The eluates were evaporated, redissolved inhexanes and purified on a column of silica gel in the same solvent. Thefractions were monitored by thin layer chromatography. The initial cutcontained two spots, the next a trace of the upper spot and thesubsequent ones only the lower spot. The latter two were evaporatedseparately and analyzed by GC showing. 66 and 86% purity respectively.These eluates were combined and evaporated in vacuo to give 3.0 g of1-propyl-4-trimethylsilybenzene. The liquid was combined with 10 mL ofmethanol and 0.16 g of potassium carbonate and stirred at roomtemperature for three hours. The mixture was partitioned between hexanesand 0.5 N aqueous HCl. The organic layer was washed twice with water anddried over sodium sulfate. Evaporation of the filtered extracts gave1.96 g of a honey colored liquid, 1-ethynyl-4-n-propylbenzene, 75.8%purity by GC.

The subsequent steps in the preparation of the subject compound followedthe general procedure of Example 33, giving 90 mg of2-amino-4-(4-trans-hydroxycyclohexylamino)-5-(4-propylphenylethynyl)pyrimidinehydrochloride, m.p. 198–200° C.

EXAMPLE 38

Preparation of2-amino-4-(4-hydroxyanilino)-5-(4-methoxyphenylethynyl)pyrimidinehydrochloride

The compound was prepared following the general procedures of examples 8and 16. The diisopropylmethine protecting group on the 2-aminosubstituent was removed by refluxing in ethanol with three equivalentsof 6 N aqueous HCl for one hour to give2-amino-4-(4-hydroxyanilino)-5-(4-methoxyphenylethynyl)pyrimidinehydrochloride. m.p. 220–230° C. with decomposition.

EXAMPLE 39

Preparation of2-amino-5-(4-chlorophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine-O-dimethylphosphate

2-Amino-5-(4-chlorophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine(3.43 g) was dissolved in dry tetrahydrofuran (150 mL) under nitrogen.The solution was cooled to −78° C. in a dry ice/acetone bath and asolution of lithium diisopropylamide (5.2 mL, 2.0 mM in THF) was addedin portions. After an additional one hour, dimethylchlorophosphate (1.52g) was added, the cooling bath was removed, and the mixture was allowedto warm to ambient temperature and stir overnight. The mixture wasstripped in vacuo and the residue was partitioned betweendichloromethane:ethyl acetate (200 mL, 3:1 v/v) and washed withsaturated aqueous sodium bicarbonate (50 mL). The organic phase wasseparated, dried (Na₂SO₄), filtered, and stripped in vacuo. The residuewas purified by chromatography on aluminum oxide (grade I, neutral)using ethyl acetate as eluent. Homogeneous fractions by tic were pooledand stripped in vacuo to give 1.68 g.2-amino-5-(4-chlorophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine-O-dimethylphosphate as a yellow foam.

Example 40

Preparation of5-(4-chlorophenylethynyl)-2-formamido-4-(4-oxocyclhexyloxy)pyrimidineethylene ketal

1,4-Dioxaspiro[4,5]decane-8-ol (1.74 g) was dissolved in drydimethylformamide (40 mL) under a nitrogen atmosphere and sodium hydride(440 mg, 60% oil dispersion) was added.4-Chloro-5-(4-chlorophenylethynyl)-2-dimethylaminomethyleneaminopyrimidine(3.19 g) was then added in one portion after hydrogen evolution hadsubsided. The mixture was stirred for 2 hours, stripped in vacuo, andthe oily residue was redissolved in ethyl acetate (250 mL). The solutionwas washed with water (3×200 mL), brine (1×200 mL), dried (Na₂SO₄),filtered, and stripped in vacuo. The residue was dissolved indichloromethane and purified by chromatography on silica gel (50 g) witha dichloromethane/ethyl acetate gradient. Fractions containing theproduct by tic were pooled and stripped in vacuo. The residue wasrecrystallized from hot ethyl acetate to give 1.89 g. of5-(4-chlorophenylethynyl)-2-formamido-4-(4-oxocyclohexyloxy)pyrimidineethylene ketal.

EXAMPLE 41

Preparation of 2-amino-5-(4-chlorophenylethynyl)-4-(4-oxocyclohexyloxy)pyrimidine

5-(4-Chlorophenylethynyl)-2-formamido-4-(4-oxocyclohexyloxy)pyrimidineethylene ketal (1.66 g) was dissolved in tetrahydrofuran (75 mL) and 6Maqueous hydrochloric acid (10 mL). The mixture was stirred at ambienttemperature for 3 hours and stripped in vacuo. The residue waspartitioned between water and ethyl acetate (150 mL) and basified with2M aqueous sodium hydroxide. The organic phase was washed with water(1×100 mL), brine (1×100 mL), dried (Na₂SO₄), filtered, and stripped invacuo. The residue was recrystallized from hot 2-propanol to give2-amino-5-(4-chlorophenylethynyl)-4-(4-oxocyclohexyloxy)pyrimidine: 0.88g; m.p. 168–172° C.

EXAMPLE 42

Preparation of2-amino-5-(4-chlorophenylethynyl)-4-[2-(2-hydroxyethoxy)ethoxy]pyrimidine

11 g of Diethylene glycol and 0.78 g of a 60% suspension of sodiumhydride in mineral oil were stirred in 200 ml of tetrahydrofuran (driedover sieves) for 15 minutes then 1.3 g of4-chloro-5-(4-chlorophenylethynyl)-2-formamido-pyrimidine was added andthe mixture was stirred at 25° C. in a dry atmosphere (drying tube) for40 hours. The reaction mixture was then evaporated under reducedpressure at 55° C. The resulting syrup was stirred with 250 ml of ethylacetate, 125 ml of saturated aqueous sodium bicarbonate and 125 ml ofwater for 15 minutes. The organic phase was washed with 250 ml of waterand then 100 ml of brine. After drying over sodium sulfate, the filteredsolution was combined with 16 g of Silica gel 60 (230–400 mesh) andevaporated under reduced pressure. The solids were applied to column ofsilica gel 60 (2.5×9.5 cm). The final height of the column was 16 cm.After eluting the column with increasing concentrations of ethyl acetatein dichloromethane, the product-rich fractions were combined and thesolvent evaporated under reduced pressure. The product wasrecrystallized twice from ethyl acetate to give 0.75 g of the desiredproduct, m.p. 142–143° C.

EXAMPLE 43

Preparation of 2-amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyphenoxy)pyrimidine

The compound was prepared following the general method of Example 42substituting hydroxyquinone for diethylene glycol as the startingmaterial. m.p. 250–251° C.

EXAMPLE 44

Preparation of (I)2-amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyphenylthio)pyrimidine, and(II)5-(4-chlorophenylethynyl)-2-formamido-4-(4-hydroxyphenylthio)pyrimidine

0.45 g of 4-mercaptophenol and 0.86 g of a 60% suspension of sodiumhydride in mineral oil were stirred in 200 ml of tetrahydrofuran (driedover sieves) for 45 minutes then 2.17 g of4-chloro-5-(4-chlorophenylethynyl)-2-formamido-pyrimidine was added andthe mixture was stirred at 25° C. under nitrogen for 5.5 hours. Thereaction mixture was then filtered and the filtrate evaporated underreduced pressure at 50° C. The resulting residue was stirred with 300 mlof ethyl acetate and 250 ml of water for 45 minutes. The organic phasewas washed with 250 ml of water and then 100 ml of brine. After dryingover stirred sodium sulfate for 6.5 hrs. the cloudy suspension wasfiltered and the filtrate was combined with 11 g of silica gel 60(230–400 mesh) and evaporated under reduced pressure at 50° C. The driedsolids were applied to a column of silica gel 60 (2.5×6 cm). The finalheight of the column was 12 cm. After eluting the column with increasingconcentrations of ethyl acetate in methylene chloride, the fractionswere allowed to stand at 25 ° C. for 48 hours. Precipitates formed intwo groups of fractions. Each was collected separately by filtration andwashed with methylene chloride. The white solid from the earlierfractions was dried in vacuo at 105° C., m.p. 266–267° C. (0.13 g). Theelemental analysis was consistent with the structure5-(4-chlorophenylethynyl)-2-formamido-4-(4-hydroxyphenylthio)pyrimidine.The light yellow solid obtained from the later fractions was dried invacuo at 105° C., m.p. 261–262° C. (0.18 g). The elemental analysis wasconsistent with the structure2-amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyphenylthio)pyrimidine.

Compounds (I) and (II) of Example 44 are subject to ex vivo or in vivooxidation at the 4-position to produce the corresponding sulfoxideand/or sulfone derivatives, and such derivatives compounds are includedwithin the scope of the present invention.

Assay for Activity

The compounds of the present invention were assayed for neurotrophicactivity as follows:

A. Screen for NGF-Like Activity:

Cultured PC12 cells (rat adrenal pheochromocytoma from ATCC) havereceptors for NGF. Responses include promotion of neurite outgrowth andelevation of choline acetyltransferase (ChAT) (L. A. Greene and A. S.Tischler, Cell Neurobiol., 3, 373 (1982)).

The following assay is modified from that described in H L White and P WScates, Neurochem. Res., 16, 63 (1991). PC12 cells were cultured at 37°C. in RPMI supplemented with HEPES buffer, pH7.5 (to 10 mM), fetalbovine serum, horse serum, glutamine, penicillin, streptomycin andnon-essential amino acids. Cultures were split 1:3 every 3 to 4 days.Exponentially dividing cells were plated into fresh medium oncollagen-coated 12-well plastic dishes (10⁵ cells/well). After allowingone day for cell attachment, the medium was replaced with low serummedium, with or without test compounds with each condition intriplicate. The medium may contain up to 0.2% ethanol, which was used asa solvent for most compounds tested. Cells were examined formorphological changes using an Olympus IMT-2 inverted researchmicroscope. After 3 days incubation with test compounds, medium wasremoved and replaced with 0.2 ml of lysis and ChAT assay mixture. Theplates were incubated at 37° C. for 2 hours and then placed into afreezer at −20° C.

Compounds are judged NGF-like in this primary screen if they (1)increase the activity of ChAT, (2) enhance NGF-stimulated neuriteoutgrowth or (3) potentiate or appear additive with the action of NGFitself.

B. Choline Acetyltransferase (ChAT) Assays:

The assay mixture contained 100 mM phosphate, pH7.4, 0.1% NP40, 150 mMNaCl, 1.5 mM choline, 10 mM EDTA, 0.1 mM eserine, 0.1 mM acetyl-coenzymeA and about 0.5 uCi (40–70 Ci/mol) [14C]acetyl-coenzyme A in each ml ofmixture. Thawed and lysed cell reaction mixtures were diluted to 1 mlwith water and transferred to 7 ml scintillation vials containing 5 mlof extraction/scintillation fluid solution (50 mg triphenyl borate, 50mg PPO, 20 mg POPOP per 100 ml of 20% acetonitrile/80% toluene) andvortexed for 10 seconds. After all 20 diluted well contents weretransferred and mixed, all the vials were vortexed again for 30 seconds,rotated for about 2 hours, and then vortexed once more. The vials werecentrifuged at 3000 rpm (rmax.=16 cm) for 15 minutes and then counted ina Beckman LS6500 scintillation counter. Background counts from reactionmixtures with extracts from non-stimulated cells (no NGF and no testcompound) were subtracted from reaction product counts beforecomparisons of ChAT activities were made.

The following data were obtained for representative compounds of thepresent invention which (1) increased the activity of cholineacetyltransferase ChAT), (2) enhanced NGF-stimulated neurite outgrowthand/or (3) potentiated or appeared additive with the action of NGFitself. The concentration at which the test compound doubled the ChATactivity over the activity with NGF alone (no test compound) wasrecorded as the EC_(2x) value. Among the more active compounds of thepresent invention are the following:

Compound of EC_(2×) (uM) Example 4 0.2 Example 9 0.1 Example 12 0.2Example 13 0.3 Example 14 0.5 Example 23 0.3 Example 26 0.2

1. A compound of Formula I:

wherein Z is O, NH or S, and m is 0 or 1; R₁ is(C2–6alkyl)_(a)(C3–10cycloalkyl, C2–9heterocycloalkyl, C5–10aryl, orC4–9heteroaryl)_(b)(C1–6alkyl)_(c), wherein a, b and c are independently0 or 1, provided that at least one of a, b and c is 1 and if b is 0,then c is also 0, further providied that, when a is 1, the C2–6alkylgroup is the point of attatchment and, when a is 0, the cyclic moity ofR₁ is the point of attatchment, and wherein the hetrogroups include from1 to 4 hetroatoms selected fron the group consisting of N, O and S, andthe C and N atoms of the R₁ may optionally be substituted woth one ormore substituents selected from the group consisting of: OH; halogen:thio; oxo; thioxo; carboxy; carboxamide; C1–7alkylcarbonyl;C1–7alkylcarbonyloxy C1–7alkylthiocarbonyl; C1–8alkyloxy;hydroxyC2–8alkyloxy; di-C1–8alkylphosphate ester C1–8alkylthio;hydroxyC2–8alkylthio; C1–8alkylsulfinyl; C1–8alkylsulfonyl;C1–5alkyloxyC1–5alkyl; C1–5alkylthioC1–5alkyl;C1–5alkylsulfinylC1–5alkyl; and C1–5alkylsulfonylC1–5alkyl; R₂ isselected from the group consisting of H, NH₂ and NH—CO—R₃, where R₃ is Hor C1–12 alkyl; and X is C6–10aryl optionally substituted with one ormore substituents (y) selected from the group consisting of: OH; NO₂ NH₂NH—CO—R₄ where R₄ is H, C1–12alkyl, aryl or (C1–6alkyl)aryl halogen;C1–6alkyl; hydroxyC1–6alkyl; oxoC2–7alkyl; C2–7alkenyl; C2–7alkynyl;C1–6alkoxy; CF₃; CF₃C1–6alkyl; OCF₃; and CF₃C1–6alkoxy; or apharmaceutically acceptable salt thereof.
 2. A compound of claim 1,wherein m is 1 and X is phenyl.
 3. A compound of claim 1, wherein m is1, X is phenyl and R₁ is C2–6alkyl, C3–10cycloalkyl, C6–10aryl, orC6–10arylC2–6alkyl.
 4. A compound of claim 1, wherein m is 1, X isphenyl and R₁ is ethyl, cyclohexyl, phenyl or phenylethyl.
 5. A compoundof claim 1, wherein m is 0, X is phenyl and R₁ is piperidino orpiperazino.
 6. A compound of claim 1 selected from:2-Amino-5-(4-chlorophenylethynyl)-4-(4-acetylpiperazino)pyrimidine,4-(trans-4-Hydroxycyclohexylamino)-5-phenylethynylpyrimidine,4-[2-(2-Hydroxyethoxy)ethylamino]-5-phenylethynylpyrimidine,5-(4-Chlorophenylethynyl)-4-[2-(2-hydroxyethoxy)ethylamino]pyrimidine,2-Amino-5-(4-chlorophenylethynyl)-4-[2-(2-hydroxyethoxy)ethylamino]pyrimidine,4-(4-(2-Hydroxyethyl)piperazino)-5-phenylethynylpyrimidine,2-Amino-4-(4-(2-hydroxyethyl)piperazino)-5-phenylethynylpyrimidine,2-Amino-5-(4-chlorophenylethynyl)-4-(4-(2-hydroxyethyl)piperazino)pyrimidine,4-(4-Hydroxypiperidino)-5-phenylethynylpyrimidine,5-(4-Chlorophenylethynyl)-4-(4-hydroxypiperidino)pyrimidine,2-Amino-4-(4-hydroxypiperidino)-5-phenylethynylpyrimidine,2-Amino-5-(4-chlorophenylethynyl)-4-(4-hydroxypiperidino)pyrimidine,4-(2-Hydroxyethylamino)-5-phenylethynylpyrimidine,2-Amino-4-(2-hydroxyethylamino)-5-phenylethynylpyrimidine,2-Amino-4-(4-hydroxyanilino)-5-phenylethynylpyrimidine,2-Amino-4-(4-trans-hydroxycyclohexylamino)-5-(4-n-pentylphenylethynyl)pyrimidine,2-Acetamido-4-(4-trans-acetoxycyclohexylamino)-5-(4-chlorophenylethynyl)pyrimidine,2-Amino-5-(4-t-butylphenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine,2-Amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyphenylethylamino)pyrimidine,2-Amino-4-(4-hydroxyanilino)-5-(4-methoxyphenylethynyl)pyrimidine,2-Amino-5-(4-propylphenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine,2-Amino-4-(4-hydroxy-2-methylanilino)-5-(4-chlorophenylethynyl)pyrimidine,2-Amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyanilino)pyrimidine,2-Amino-5-(4-chlorophenylethynyl)-4-(4-oxocyclohexyloxy)pyrimidine,2-amino-5-(4-chlorophenylethynyl)-4-[2-(2-hydroxyethoxy)ethoxy]pyrimidine,2-amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyphenoxy)pyrimidine,2-amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyphenylthio)pyrimidine,5-(4-chlorophenylethynyl)-2-formamido-4-(4-hydroxyphenylthio)pyrimidine,4-(4-Hydroxyanilino)-5-phenylethynylpyrimidine,5-(4-Chlorophenylethynyl)-4-(4-hydroxyanilino)pyrimidine,2-Amino-4-[2-(2-hydroxyethoxy)ethylamino]-5-(4-methylphenylethynyl)pyrimidine,2-Amino-4-(trans-hydroxycyclohexylamino)-5-(4-methylphenylethynyl)pyrimidine,5-(4-Chlorophenylethynyl)-2-formamido-4-(4-trans-hydroxycyclohexylamino)pyrimidine,2-Amino-5-(3,4-dichlorophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine,2-Amino-5-(4-chlorophenylethynyl)-4-(4-oxocyclohexylamino)pyrimidine,2-Amino-5-(2-chlorophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine,2-Amino-5-(4-bromophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine,2-Amino-5-(4-chlorophenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine-O-dimethylphosphate ester,2-Amino-5-(4-chlorophenylethynyl)-4-(3,4-dimethoxyanilino)pyrimidine,and5-(4-Acetamidophenylethynyl)-2-amino-4-(4-trans-hydroxycyclohexylamino)pyrimidine.
 7. A compound of claim 1 selected from:5-(4-Chlorophenylethynyl)-4-(trans-4-hydroxycyclohexylamino)pyrimidine,2-Amino-5-(4-chlorophenylethynyl)-4-(4-hydroxyanilino)pyrimidine,2-Amino-4-(trans-4-hydroxycyclohexylamino)-5-phenylethynylpyrimidine,2-Amino-5-(4-chlorophenylethynyl)-4-(trans-4-hydroxycyclohexylamino)pyrimidine,2-Amino-5-(4-chlorophenylethynyl)-4-(cis-4-hydroxycyclohexylamino)pyrimidine,2-Amino-4-[2-(2-hydroxyethoxy)ethylamino]-5-phenylethynylpyrimidine,2-Amino-5-(4-chlorophenylethynyl)-4-(2-hydroxyethylamino)pyrimidine, and2-Amino-5-(4-ethylphenylethynyl)-4-(4-trans-hydroxycyclohexylamino)pyrimidine.8. A compound of claim 1 according to Formula IA:

wherein p is 0, 1 or 2, and each y (which may be the same or different),R₁ and R₂ are as defined in claim 1, or a pharmaceutically acceptablesalt thereof.
 9. A compound of claim 8, wherein R₁ is C2–6alkyl,C3–10cycloalkyl, C6–10aryl, or C6–10arylC2–6alkyl.
 10. A compound ofclaim 8, wherein R₁ is hydroxycyclohexyl, hydroxyphenyl,hydroxyphenylethyl, hydroxyethyl or hydroxyethoxyethyl.
 11. A compoundof claim 1 according to Formula IB

wherein p is 0, 1 or 2, and each y (which may be the same or different),R₁ and R₂ are as defined in claim 1, or a pharmaceutically acceptablesalt thereof.
 12. A compound of claim 11, wherein R₁ is C2–6alkyl,C3–10cycloalkyl, C6–10aryl, or C6–10arylC2–6alkyl.
 13. A compound ofclaim 11, wherein R₁ is hydroxycyclohexyl, hydroxyphenyl,hydroxyphenylethyl, hydroxyethyl or hydroxyethoxyethyl.
 14. A compoundof claim 1 according to Formula IC

wherein p is 0, 1 or 2, and each y (which may be the same or different),R₁ and R₂ are as defined in claim 1, or a pharmaceutically acceptablesalt thereof.
 15. A compound of claim 14, wherein R₁ is C2–6alkyl,C3–10cycloalkyl, C6–10aryl, or C6–10arylC2–6alkyl.
 16. A compound ofclaim 14, wherein R₁ is hydroxycyclohexyl, hydroxyphenyl, orhydroxyethoxyethyl.
 17. A pharmaceutical composition, comprising acompound of claim 1 and a pharmaceutically acceptable carrier therefor.18. A method of treating a mammal having a neurodegenerative orneurological disorder of the central or peripheral nervous systemselected from the group consisting of Alzheimer's disease, peripheralneuropathy, senile dementia, seizure disorders, Huntington's disease,and Parkinson's disease, which comprises administering to said mammal atherapeutically effective amount of a compound of claim
 1. 19. Apharmaceutical composition, comprising a compound of claim 6 and apharmaceutically acceptable carrier therefor.
 20. A pharmaceuticalcomposition, comprising a compound of claim 7 and a pharmaceuticallyacceptable carrier therefor.
 21. A method of treating a mammal having aneurodegenerative or neurological disorder of the central or peripheralnervous system selected from the group consisting of Alzheimer'sdisease, peripheral neuropathy, senile dementia, seizure disorders,Huntington's disease, and Parkinson's disease, which comprisesadministering to said mammal a therapeutically effective amount of acompound of claim
 6. 22. A method of treating a mammal having aneurodegenerative or neurological disorder of the central or peripheralnervous system selected from the group consisting of Alzheimer'sdisease, peripheral neuropathy, senile dementia, seizure disorders,Huntington's disease, and Parkinson's disease, which comprisesadministering to said mammal a therapeutically effective amount of acompound of claim
 7. 23. A method according to claim 18, wherein thedisorder is Alzheimer's disease.
 24. A method according to claim 21,wherein the disorder is Alzheimer's disease.
 25. A method according toclaim 22, wherein the disorder is Alzheimer's disease.
 26. A methodaccording to claim 18, wherein the disorder is peripheral neuropathy.27. A method according to claim 21, wherein the disorder is peripheralneuropathy.
 28. A method according to claim 22, wherein the disorder isperipheral neuropathy.
 29. A method according to claim 18, wherein thedisorder is senile dementia.
 30. A method according to claim 21, whereinthe disorder is senile dementia.
 31. A method according to claim 22,wherein the disorder is senile dementia.
 32. A method according to claim18, wherein the disorder is a seizure disorder.
 33. A method accordingto claim 21, wherein the disorder is a seizure disorder.
 34. A methodaccording to claim 22, wherein the disorder is a seizure disorder.
 35. Amethod according to claim 18, wherein the disorder is Huntington'sdisease.
 36. A method according to claim 21, wherein the disorder isHuntington's disease.
 37. A method according to claim 22, wherein thedisorder is Huntington's disease.
 38. A method according to claim 18,wherein the disorder is Parkinson's disease.
 39. A method according toclaim 21, wherein the disorder is Parkinson's disease.
 40. A methodaccording to claim 22, wherein the disorder is Parkinson's disease.